Amgen and Sanofi end epic battle over Praluent and Repatha

The dispute between Amgen on the one side and Sanofi and Regeneron on the other is probably one of the longest and most intense patent disputes in recent history. Both sides offer cholesterol-lowering drugs. Amgen sells its PCSK9 inhibitor Repatha with the active ingredient evolocumab. Sanofi and Regeneron market their drug under the brand name Praluent. While Sanofi markets Praluent, Regeneron owns the patents.

In Europe and the US, Amgen and Sanofi, along with Regeneron, have battled over Praluent and Repatha since 2014. Initially, they fought in national patent courts. Both companies then escalated their dispute to the UPC. Most recently, the dispute focused primarily on the UPC and the European Patent Office. There, both sides attacked the rival product with lawsuits against each other.

However, in various European countries, the main focus was on claims for damages from lawsuits with which Amgen had attempted to force Praluent out of the market in the early phase of the dispute. In Germany, for example, there were proceedings at the Regional and Higher Regional courts as well as at the Federal Court of Justice. In Japan, too, both sides have since met in court.

Withdrawals begin

The parties have now agreed to end the years-long dispute. Several sources confirmed this to JUVE Patent. In addition, both sides have mutually withdrawn their attacks on important patents at the EPO. For example, Sanofi and Regeneron withdrew their appeals in the opposition case over Amgen’s EP 3 666 797. For its part, the US pharmaceutical giant withdrew its appeal against Regeneron’s EP 3 536 712 B1.

No appeals have yet been withdrawn at the UPC. However, according to a source, the lawyers on both sides are currently filing corresponding applications.

The companies apparently reached an agreement at the end of last week to end all proceedings relating to Praluent and Repatha. Further details of the settlement are not known. So far, Amgen and Sanofi have not made any announcement in this regard.

Surprising end

In view of the intensity with which both sides fought for over ten years, the settlement comes as a surprise. It is not known what brought about the agreement.

After Sanofi and Regeneron had had the upper hand for some time, Amgen had recently begun to turn the tables. However, there were no indications they would reach an agreement anytime soon.

In November 2025, the UPC Court of Appeal found Amgen’s EP 797 valid (case IDs: UPC_CoA_528/2024 and UPC_CoA_529/2024). This was a major win for Amgen. The ruling reopened the infringement case at Munich local division. The court would have heard the case in November (case ID: UPC_CFI 14/2023).

In April last year, the European Patent Office ruled that Amgen’s EP 797 is valid as granted. The Boards of Appeal have now cancelled the oral hearing regarding Sanofi’s and Regeneron’s appeal, which was scheduled for mid-April.

Many lawyers involved

Over the years, a large number of lawyers and patent attorneys have been involved in the dispute. In Europe, Amgen relied mainly on teams from Brinkhof and Bardehle Pagenberg. Brinkhof partner Koen Bijvank played a central role in the latest EPO proceedings. Bardehle Pagenberg partner Jochen Heselberger led the UPC cases.

Amgen also works with Osborne Clarke and df-mp in other proceedings.

Sanofi and Regeneron retained their usual advisors Carpmaels & Ransford and Hoffmann Eitle, both previously involved in Amgen disputes. Daniel Wise led the Carpmaels team.

Former Hoffmann Eitle partner Niels Hölder led the infringement cases for Regeneron, but at the beginning of 2026 he moved to Carpmaels & Ransford.

Hoffmann Eitle remained involved via patent attorney Gregor König. Jörg Zwicker from Munich patent attorney firm ZSP also advised. Arnold Ruess partner Bernhard Arnold was primarily involved in the proceedings concerning damages claims in previous Amgen lawsuits.

In the US proceedings, both Quinn Emanuel Urquhart & Sullivan and McDermott Will & Emery represented Amgen at times, whereas Arnold & Porter represented Sanofi.